Inguinal hernia is a common disease and causes significant morbidity if left untreated. With the advances of laparoscopic approach of extra-peritoneal hernioplasty, it significantly reduces the post-operative pain and lead to a better quality of life with higher acceptance to patients.However, similar to traditional Litchenstein approach, post operative seroma formation is still a common problem encountered after surgery. Numerous method has been described to reduce chance of seroma formation, however, none was proven to be effective except pre-peritoneal drainage. There are currently 2 large retrospective non-randomized cohort study to evaluate the effectiveness of preperitoneal drainage available for reference. We therefore study the feasibility and efficacy of preperitoneal drainage with large scale randomized trial.